Space-Time Engineering

But this was supposed to be a conservative implementation, utilizing
nothing more exotic than directed ultrarelativistic neutron stars. Mitch Porter

This section deals with technology and science which uses the properties
of ####space-time
in novel ways, or actually changes the properties (like wormholes
and basement universes).
These technologies are naturally very speculative at present, but the
scientific results below give an inkling of what may be possible.

Sections

Artificial gravity. A short description of
the torus method of Robert Forward of creating (a rather weak) gravity
field. Cosmological Waveguides
for gravitational waves by G. Bimonte, S. Capozziello, V. Man'ko,
G. Marmo. Apparently gravitational waves can be led along waveguides of
dust, which might be useful in gravity manipulation. The gravitational wave
rocket by W. B. Bonnor and M. S. Piper. In principle it ought to be
possible to move a rocket using gravitational waves.

FTL - Faster Than Light Travel

Travelling faster than light is an old dream, complicated due to relativity
and causality (FTL travel can cause causal loops in relativity). One way
of achiving extreme speeds in general relativity is to employ suitable warps
of spacetime, but the principal difficulties are severe. Another kind of
solution is wormholes.

Time Travel

Time travel may appear even more outrageous than FTL, but both phenomena
are closely linked to each other. Causal loops (Closed Timelike Curves,
CTCs) exist in some solutions to general relativity. The question is whether
they can occur in physically relevant spacetimes and how paradoxes are avoided.

Wormholes

Wormholes are shortcuts through spacetime, connecting two distant locations
through a short "tunnel". They can exist in general relativity,
but the main issue is whether they are traversable and possible to create.

Basement Universes

According to some theories, it is possible to spawn new universes (i.e.
independent volumes of spacetime) through various means. This could be
used for a variety of things, such as computation or escape from a unsuitable
spacetime.